Cathode cylinder for use in metal-air fuel cell battery systems and method of fabricating the same

• US 6,218,034 B1
• Filed: 08/10/1998
• Issued: 04/17/2001
• Est. Priority Date: 10/06/1997
• Status: Expired due to Fees

• Current Assignee: Reveo, Inc.
• Original Assignee: Reveo, Inc.
• Inventors: Faris, Sadeg M., Yao, Wayne, Tsai, Tsepin, Chen, Muguo, Legbandt, Thomas J.
• Primary Examiner(s): KALAFUT, STEPHEN J
• Application Number:
  US09/232,327
• Time in Patent Office: 981 Days
• Field of Search: 429/27, 429/31, 429/40, 429/68, 429/69, 429/127, 427/115, 502/101
• US Class Current: 429/404
• CPC Class Codes: H01M 10/4214 Arrangements for moving electrodes or electrolyte
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 12/08 composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
• CPC Class Codes: H01M 2004/024 Insertable electrodes
• CPC Class Codes: H01M 2300/0085 Immobilising or gelification of electrolyte
• CPC Class Codes: H01M 4/42 Alloys based on zinc
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 50/46 Separators, membranes or diaphragms characterised by their combination with electrodes
• CPC Class Codes: H01M 6/5011 for several cells simultaneously or successively
• CPC Class Codes: H01M 8/184 Regeneration by electrochemical means
• CPC Class Codes: H01M 8/186 by electrolytic decomposition of the electrolytic solution or the formed water product
• CPC Class Codes: H01M 8/22 Fuel cells in which the fuel is based on materials comprising carbon or oxygen or hydrogen and other elements; Fuel cells in which the fuel is based on materials comprising only elements other than carbon, oxygen or hydrogen
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

In an air-metal fuel cell battery (FCB) system, wherein metal-fuel tape, the ionically-conductive medium and the cathode structures are transported at substantially the same velocity at the locus of points at which the ionically-conductive medium contacts the moving cathode structure and the moving metal-fuel tape during discharging and recharging modes of operation. In a first generalized embodiment of the present invention, the ionically-conductive medium is realized as an ionically-conductive belt, and the metal-fuel tape, ionically-conductive belt, and movable cathode structure are transported at substantially the same velocity at the locus of points which the ionically-conducing belt contacts the metal-fuel tape and the cathode structure during system operation. In a second generalized embodiment of the present invention, the ionically-conductive medium is realized as a solid-state (e.g. gel-like) film layer integrated with the metal-fuel tape, and the metal-fuel tape, ionically-conductive film layer and movable cathode structure are transported at substantially the same velocity at the locus of points which the ionically-conducing film layer contacts the metal-fuel tape and the cathode structure during system operation. In a third generalized embodiment of the present invention, the ionically-conductive medium is realized as a solid-state film layer integrated with the movable cathode structure, and the metal-fuel tape, ionically-conductive film layer and movable cathode structure are transported at substantially the same velocity at the locus of points which the ionically-conducing film layer contacts the metal-fuel tape and the cathode structure during system operation. By transporting the movable cathode structure, ionically contacting medium and metal-fuel tape within the system as described above, generation of frictional forces among such structures are minimized during system operation, and thus the damage to the cathode structure and metal-fuel tape is substantially reduced.

Claims

1. A cathode cylinder for use in a metal-air fuel cell battery system, said cathode cylinder comprising:

a cathode structure of cylindrical geometry having a hollow central core, an outer surface, and a constitution allowing oxygen to flow through said outer surface along said cathode structure towards an ionically-conductive medium in contact with said outer surface during operation of said metal-air fuel cell battery system;

an axis of rotation about which said cathode structure rotates during operation of said metal-air fuel cell battery system, and

said cathode structure further embodying

a catalytic material for supporting a catalytic reaction at the interface formed between said ionically-conductive medium and said outer surface as said metal-fuel material is transported over said ionically-conductive medium in contact with said outer surface during operation of said metal-air fuel cell battery system, and

a current-collecting material for collecting electrical current produced as said metal-fuel material is transported over said ionically-conductive medium in contact with said outer surface during operation of said metal-air fuel cell battery system,

wherein said ionically-conductive medium comprises a solid-state film having a gelatinous consistency and ionically-conductive properties, applied to said outer surface of said cathode structure.

2. The cathode cylinder of claim 1, which further comprises

a cylindrical support structure for supporting said cathode structure during rotation about said axis of rotation.

3. The cathode cylinder of claim 2, wherein said cylindrical support structure has a hollow central core and perforations formed therein for enabling the passage of oxygen during operation of said metal-air fuel cell battery system.

5. The cathode cylinder of claim 1, wherein said catalytic material comprises platinum.

4. A cathode cylinder for use in a metal-air fuel cell battery system, said cathode cylinder comprising:

a cathode structure of cylindrical geometry having a hollow central core, an outer surface, and a constitution allowing oxygen to flow through said outer surface along said cathode structure towards an ionically-conductive medium in contact with said outer surface during operation of said metal-air fuel cell battery system;

an axis of rotation about which said cathode structure rotates during operation of said metal-air fuel cell battery system, and

said cathode structure further embodying

a catalytic material for supporting a catalytic reaction at the interface formed between said ionically-conductive medium and said outer surface as said metal-fuel material is transported over said ionically-conductive medium in contact with said outer surface during operation of said metal-air fuel cell battery system, and

a current-collecting material for collecting electrical current produced as said metal-fuel material is transported over said ionically-conductive medium in contact with said outer surface during operation of said metal-air fuel cell battery system,

wherein said current collecting material comprises a nickel mesh fabric material embedded with said catalytic material, carbon and binder material.

6. A cathode cylinder for use in a metal-air fuel cell battery system, said cathode cylinder comprising:

a cathode structure of cylindrical geometry having a hollow central core, an outer surface, and a constitution allowing oxygen to flow through said outer surface along a substantial portion of said cathode structure towards an ionically-conductive medium in contact with said outer surface during operation of said metal-air fuel cell battery system;

an axis of rotation about which said cathode structure rotates during operation of said metal-air fuel cell battery system, and

said cathode structure further embodying

a catalytic material for supporting a catalytic reaction at the interface formed between said ionically-conductive medium and said outer surface as said metal-fuel material is transported over said ionically-conductive medium in contact with said outer surface during operation of said metal-air fuel cell battery system, and

a current-collecting material for collecting electrical current produced as said metal-fuel material is transported over said ionically-conductive medium in contact with said outer surface during operation of said metal-air fuel cell battery system,

wherein said current collecting material comprises a nickel sponge material embedded with said catalytic material, carbon and binder material.

7. The cathode cylinder of claim 6, wherein said catalytic material comprises platinum.